Tube ice-making apparatus



Feb. 8, 1955 N. E. HOPKINS 2,701,452

TUBE ICE-MAKING APPARATUS Filed July 28, 195o s sheets-sheet `1,

Y @if a ATTORNEY Feb. 8, 1955 N. E. HOPKINS TUBE ICE- MAKING APPARATUSFiled July 28, -1950 5 Sheets-Sheet 2 INVENTOR ATTORN Feb. 8, 1955 N. E.HOPKINS TUBE 1cEMAK1NG APPARATUS 5 Sheets-Sheet 3 Filed July 28, 1950 mP m JW m MA Q@ @IL AS ww IT l l I I I I l l l l l l I I I I l TUBEICE-MAKHNG APPARATUS Neil E. Hopkins, York, Pa., assignor to FlalriceCorporation, Brooklyn, N. Y., a corporation of Delaware Application.lluly 28, 1950, Serial No. 176,270

Claims. (Cl. 62--105) This invention relates vto refrigeration, and morein particular to making ice in the form of cubes or the like by the useof machines such as those disclosed in the copending applications ofMeldon Gerald Leeson: Serial No. 573,939, filed January 22, 1945, nowPatent 2,524,815, and Serial No. 686,021, filed July 24, 1946, nowPatent 2,549,747, and also in the copending applications of William M.Grandia, Serial No. 57,158, led October 29, 1948, now Patent 2,593,874,and of Rodney F. Lauer and Claude V. Shurtluff, Serial No. 174,216,tiled July 17, 1950, and issued as Patent No. 2,633,005.

The above-identified applications disclose 'machines and methods formaking ice in the form of cubes which may have cylindrical holestherethrough. The illustrative embodiment of the present invention is inthe form of an embodiment of or an improvement on the copendingapplication of Rodney F. Lauer and Claude V. Shurtluif, which inventionis disclosed specifically in apparatus which comprises an ice-makingmachine or apparatus which, except as specifically pointed out, isidentical with that disclosed in application Serial No. 57,158, which,in turn, incorporates specific structure shown in application Serial No.686,021. The structure herein disclosed is therefore described onlysufficiently for the understanding of the present invention, andreference may be had to the above-identified copending applications formore f detailed discussions of certain features of construction andoperation of this general type of apparatus.

It is an object of the present invention to provide improved apparatusof the above character and to provide an improved mode of operationthereof. It is a further object to provide improved modes of operationand control for apparatus of the above character. It is a further objectto provide for the above withapparatus which is practical in everyrespect from a commercial standpoint. These and other objects will beinpart obvious and will in part be pointed out below. y

The invention accordingly-consists in the features of construction,combinations of elements, .and arrangements of parts as will beexemplified in thestructurev to be hereinafter described` and the scopeofthe application of which will be indicated in the -following claims.

In the illustrative embodimentofthe invention disclosed in applicationSerial' No. 57,158, ice cubes are formed by tirst freezing-the water toform ice rods or columns which are square in cross-section and may havea cylindrical hole therethrough, and these columns are melted free andthen are cut or broken into lengths to form the cubes. The columns ofice are formed by flowing water through vertical freezing tubes whichform passageways along the side walls of which the water flows whilethese walls are refrigerated sufficiently to cause ice to build up. Therate of ow and the other conditions are so controlled that clear, hardice builds up in an even layer and the freezing operation is continueduntil the column is substantially solid or, if desirable, has a hole ofpredetermined size therethrough.

A harvesting operation is then started which involves melting the cubesfree so that they fall from the tubes, and as they emerge from thebottoms of the tubes they are severed into predetermined lengths to formthe cubes. During the freezing operation water is circulated through thetubes at a rate which is in excess of the amount frozen, and the waterin excess of that which is frozen is collected in a sump tank to whichfresh water is added and from which water is pumped and recirculatedthrough the freezing tubes.

ZS Patented Feb. 8, 1955 With apparatus such as that referred to above,difficulty has been encountered in producing uniform high quality icewithout the attention of an operator. Machines such as those referred toabove have, however, been sold as package units; that is, self-containedunits are built and sold for installation by the purchaser, and are putinto operation by making connections to the water supply and drain andto a source of electric power. The operation is then automatic with theice-making and harvesting operations being carried on in accordance witha controlled cycle. Under some circumstances the salt concentration ishigh so that there is a tendency for the ice to become cloudy andcommercially unacceptable, and special care must be taken to maintainthe salt concentrations within permissible limits. It is advisable,however, to avoid complicated and costly equipment and to use a minimumamount of water consistent with the production of maximum quantities ofcommercially acceptable ice.

An important feature of this type of equipment from a commercialstandpoint is that the ice produced is uniform in size and shape and, ofcourse, is of high quality; that is, the ice cubes are clear and hardand of substantially the same size and shape. It has been found,however, that apparatus such as that referred to above will, under someconditions of operation, produce ice which is not uniform and, in fact,which is not entirely satisfactory frorn a commercial standpoint. Forexample, if the ice builds up at an excessive rate in one particulartube it may freeze solid and become sub-cooled excessively prior to theend of the freezing cycle and then part or all of it may not becomedislodged during the harvesting cycle. If due to this or another cause,a body of ice remains in one of the freezing tubes after a harvestu ingcycle has been completed, there is great danger that the tube will bedamaged during the next freezing operation.

Provision has been made in apparatus of the above character forpreventing the completion of a freezing operation if one or more of thetubes are obstructed. However, it is still important to insure that icebuilds up at the desired rate in all of the freezing tubes. As indicatedabove, with this type of apparatus, when water is flowed down the innerwalls of the freezing tubes at a very rapid rate, clear and hard iceforms in an even layer. This is because the rapidly owing layer of watercovers the entire inner surfaces of each of the tubes, and this effecthas been obtained in the past by projecting individual streams of thewater against the top of each of the four side wall surfaces of eachtube. Thus four streams are projected into each tube from correspondingoutlets or openings in a nipple or water distributor in the bottom of awater header where the water is maintained under pressure by the watercirculating pump referred to above.

As discussed in the copending application of Rodney F. Lauer and ClaudeV. Shurtluff, it was found that one or more of the outlets from thesenipples was apt to become clogged; for example, by the accumulation ofcrystallized salts when the salt concentration is high. When one or moreof the water outlets in a nozzle became clogged there was acorresponding decrease in the rate at which water flowed through thattube. Thus, While the water tended to spread out over the entire innersurface of that tube, the rate of water flow was reduced because of thelesser quantity which was being delivered to the tube. This reduced rateof water flow not only caused the ice in that tube to become milky oreven white and spongy, but this reduced rate of flow caused the ice tobuild up at an increased rate so that that particular tube becamelledwith a column of ice prior to the completion of the freezingoperation in the other tubes. For example, at times the ice completelylled one tube while relatively thin shells were formed in the othertubes.

In the apparatus of Serial No. 57,158 the harvesting operation isinitiated whenever one or more of the tubes becomes lled with icesuiciently to interfere materially with the ow of water therethrough.This has been eX- tremely satisfactory as a mode of control for mostconditions of operation because the freezing is uniform in the varioustubes and they all become substantially filled with columns of ice ofhigh quaiity at substantially the aromas same time; that is, by the timeone or more of the tubes has the water tiow obstructed by the icesufliciently to initiate the harvesting operation. However, with suchcontrol it has been found that, when there is an obstruction asdiscussed above in one or more openings 1n a nipple supplying water to atube, so that ice builds up and fills that tube with ice prematurely inthe cycle, then a harvesting cycle is also started prematurely. Asindicated above, under some circumstances the one tube havingobstructions in its water supply openings is lilled with poor qualityice while the other tubes have only shells of ice in them and,therefore, the apparatus produces no ice of acceptable quality and size.

In accordance with the invention of the above-identitied application ofRodney F. Lauer and Claude V. Shurtluff, arrangement is provided forinsuring that the water will be distributed evenly and will owcontinuously down all of the tube surfaces throughout the entirefreezing cycle. That invention contemplates a water distributionarrangement wherein solid particles such as crystallized salts orforeign matter will not interfere with this flow. Thus, the freezingcycle will be carried on to completion without danger of being stoppedby the permature building up of ice in the tube. Furthermore,

the water is delivered to the tubes in such a manner that it does nottend to flow at a reduced rate through any area of the freezing surfacesof the tubes.

As indicated above the present invention is in a sense an improvementupon that disclosed in the above-identifiel application of Rodney F.Lauer and Claude V. Shuttlu The present invention provides an improvedconstruction for carrying out the above. Water tlows into the tops ofthe freezing tubes through unobstructed pipes and it hits a target whichis dish-shape so that the water is deflected radially outwardly andupwardly. The target is supported in such a way that it is rigid and yetit may be removed readily for servicing. One illustrative ernbodiment ofthe invention is particularly adapted for installation on ice-makingmachines such as the one disclosed in the above-identified coptndingapplication of William M. Grandia while the other illustrative embodi-Iment is related more closely to the apparatus disclosed in theabove-identified application of Rodney F. Lauer and Claude V. Shurtluff.

ln the drawings:

Figure l is a schematic diagram of an ice-making machine of thecharacter referred to above and incorporating the present invention;

Figure 2 is an enlarged top plan view with parts broken away of thewater distributor header of Figure l;

Figure 3 is a side elevation with parts broken away of the header ofFigure 2;

igure 4 is an end elevation of the header of Figures 2 an 3;

Figure 4A is an enlarged plan View of the water distributor outlets withthe center broken away and showing the enlarged size of the outlets tothe end tubes;

Figure 5 is an enlarged sectional View of the water distributing nozzleof Figure 3;

Figures 6 and 7 are similar to Figures 2 and 3 respectively, but showanother embodiment of the invention.

Figures 8, 9 and l0 are sectional views respectively on the lines 8 8,9-9 and 10--10 of Figure 7; and,

Figure ll is a section on the line 11-11 of Figure i0.

Referring to Figure l of the drawing there is represented schematicallyat the top a bank of sixteen freezing tubes 1 to the tops of which wateris directed by a header 3 supplied by a pump 5 from a sump tank 7. Thewater flows down the tubes and some is frozen, and the amount in excessof that frozen in the tubes returns to the sump tank. A oat valve 8connected to a source of water opens and closes automatically tomaintain a predetermined level in the tank. The freezing tubes arecooled by an evaporator 9 to which liquid refrigerant is suppliedthrough a thermostatic valve 11 having a bulb 13. The gas refrigerantfrom the evaporator is `withdrawn by a compressor having an electricmotor 14 hermetically scaled within its casing. The compressed gaspasses from the compressor 15 to a watercooled condenser 17 cooled bywater supplied through a vulve 18. The refrigerant is here liquefied andpasses to evaporator. During the harvesting cycle hot gas retrigerant ispassed from the compressor to the evaporator if.; heat the freezingtubes; accordingly, a pipel i9 (indicated by broken lines) is providedhaving a normallyclosed solenoid valve 21 therein which valve is openedto connect the outlet side of the compressor to the bottom of theevaporator.

Power to operate the machine is supplied through a main control switch23 to a pair of lines 25 and 27 which are connected directly to thecompressor motor. Line 25 is also connected to the armature 29 of adoublethrow solenoid switch 31 and also to one side of a thermostaticswitch 33. Line 27 is connected to one side of each of: the solenoidvalve 21; the ice cutter motor 37 which operates the mechanism to cutthe ice into cubes; the water pump motor 39 which drives pump 5; and thesolenoid 41 of switch 31. Switch 31 has its normallyclosed contact 43connected to the other side of the solenoid ot' valve 21 and also to theother side of motor 37; and it has its normally-opened contact 45connected to the pump motor 39 and also to one side of a thermostaticswitch 47. The other side of switch 47 is connected to solenoid 41 andto switch 33. The operation of the machine will be explained after theconstruction of the water distributor and the associated parts have beenexplained in detail.

Referring to the upper portion of Figure l, there is shown the bank ofsquare freezing tubes 1 positioned in side-by-side relationship withaplate 48 between the side walls of cach two adjacent tubes. On theopposite sides of the bank of tubes there are two evaporator sections ofevaporator 9 formed by horizontal runs of metal tubing with the sectionsbeing connected by headers. The bank of freezing tubes and theevaporator sections are covered by insulation and enclosed in a sheetmetal casing. At the top of the bank of tubes there is a horizontalwater supply header 53 which is enclosed in an insulation shell, andprojecting from the bottom wall of this header into the top of each oftubes 1 is a water distributor nozzle 54 (see Figure 3) which directswater against the inner surfaces of the four walls of its tube.

At the bottom of the freezing tubes there is an icecutting assemblywhich is not shown but is shown and described in detail in theabove-identified applications. This assembly severs the columns of icewhich are formed in the tubes into lengths to form the ice cubes whichare passed by gravity to a storage bin. At the beginning of theharvesting operation the columns of ice are released by passing hot gasinto evaporator 9 and at the same time the ice cutter assembly isstarted. This operation continues until the temperature of theevaporator rises, thus indicating that the ice has been freed and hasdropped from the freezing tubes. At this time the harvesting operationis discontinued and a new freezing operation is started. As indicatedabove, during the freezing operation water is pumped into header 3 atthe top of the freezing tubes and it ows down the entire inner surfacesof each of these tubes. The construction of header 3 is shown in Figures2 to 5 and will now be described.

Referring to Figures 2, 3 and 4 of the drawings header 3 is formed bythe elongated sheet metal supply header 53 and a parallel waterdischarge pipe or header 49 which has its right-hand end (Figure 3) bentdownwardly. The water supply header is enclosed in an insulation shelland the entire header is supported by three brackets 51 which are weldedto the supply header 53 and have their ends clamped to the top of thebank of freezing tubes. The water discharge header is supported bysixteen somewhat arcuate water overflow discharge tubes 52 (Figure 5)each of which has one end connected into the top of header 49. The otherend of each of tubes S2 projects into the water supply header 53 andthence downwardly through the bottom wall of this header. Thus. eachtube 52 connects the upper end of one of the freezing tubes to the topof header 49, and it projects through and is soldered to the watersupply header 53 and the top wall of header 49.

As indicated above, header 53 has water distributor nozzles 54 mountedin its bottom wall; illustratively, there being sixteen freezing tubesand nozzles with each tube and its nozzle being in axial alignment. Asbest shown in Flgure 5, each of the nozzles comprises a sleeve orferrule 5S and a target or delector 56. Ferrule 55 is soldered to thebottom wall of header 53 and has a central water outlet opening 57through which water is discharged from the header. Target 56 s somewhatdishshaped and it is supported by two integral arms 59 which (see Figure3) extend outwardly and upwardly and have their ends bent inwardly sothat they engage an annular groove 58 at the lower end of ferrule 55.

During operation the water from header 53 ows through each of thenozzles in a rapidly moving stream and the stream is projected againstthe upper surface of target 56. Target 56 spreads the water and causesit to flow radially in a smooth thin stream or sheet outwardly againstthe tube walls. The upturned rim of the target causes the sheet of waterto be diverted upwardly so that the water engages the tube walls atsubstantially the top of the tube. Thus, as described above, the waterflows downwardly along the tube walls and it tends to spread evenly andto flow at a rapid rate. It should b e noted that the nozzles provideunobstructed water discharge outlets from the header into the tubes.Thus, particles of even a relatively large size will pass through thenozzles and are washed down the tubes into the sump tank without in anyway obstructing the ow of water.

The water discharge header 49 is connected (Figure 1) to the downwardlyextending pipe 91 and water isvsupplied from pump 5 to header 53 througha pipe 90. The left-'hand end of header 49 is vented at the left throughan inverted U tube 92. Pipe 91 projects downwardly into the enlargedupper end of a pipe 95 which extends to the sump tank 7. Thermostaticbulb 97 of switch 47 is positioned in pipe 95 so that water flows overit from pipe 91 and the bulb is connected through a tube 98 to itsswitch.

Thel freezing operation has been described above and for more detaileddiscussions of it reference may be had to the above-identified copendingapplication. For purposes of understanding the present invention, it issufficient to point out that with the system operating as represented inFigure 1 water flows through the nozzles 54 and thence downwardlythrough the freezing tubes while the freezing tubes are cooled by therefrigeration system discussed above. Ice of high quality builds up onthe tube walls in the forms of columns or tubes which are square incross section with a central opening therethrough. As the freezingcontinues, these openings become smaller until the ow of water throughthe freezing zone is interfered with, at which time the water tends toback up into the tops of the tubes. The water which backs up in any tubetends to flow upwardly through the connecting overflow tube 52 and overinto the header 49 (see Figure 5). Water in header 49 ows to the right(Figure l) and thence downwardly through pipe 91 and over bulb 97. Thiswater is cooled and it reduces the -temperature of bulb 97sufticientlvto open switch 47 and this-initiates the harvestingoperation.

It should be noted that switch 33 has its bulb 99 positioned near thetop of the bank of freezing tubes and thisvswitch closes and the bulbtemperature rises substantially above 30 F. and the switch opens againwhen the temperature drops. Thus, during the freezing operation thisswitch is open and, therefore, the opening of switch 47 deenergizessolenoid 41 so as to drop armature 29 away from contact 45, thusstopping the pump motor 39. Armature 29 drops into engagement withcontact 43 and this energizes the solenoid of valve 21 so as to openthis valve and supply hot gas to the evaporator and it also starts thecutter motor 37.v The columns of ice are therefore thawed from thefreezing tubes and they drop down and are severed into cubes by themechanism operated by motor 37.

When the tubes are free of ice their temperature rises rapidly so thatbulb 99 is heated and its switch 33 closes. This energizes solenoid 41so as to raise armature 29 with the result that the cutter motor 37 isstopped and the solenoid of valve 21 is deenergized so that this valverecloses and hot gas is no longer suppliedto the evaporator. The raisingof armature 29 restarts the pump motor 39. ln the meantime, water hasceased to flow from the tops of the tubes through pipe 91 with theresult that the temperature of bulb 97 has risen and switch 47 hasreclosed. Thus, switch 47 provides the interlock circuit which holdssolenoid 41 energized after the next freezing operation has restartedand the cycle is therefore repeated.

Referring to Figures 6 to ll of the drawings which show anotherembodiment of the invention, a pair of sheet metal shells 60 and 61 formrespectively, a water inlet passageway 86 and a water dischargepassageway 88. These shells are fabricated of sheet metal with soligasket 80 on the inner surface of the end wall seals the openings. Theshells are clamped in place by bolts (not shown) extending through aplurality of tubular brackets 82 welded to the sidewalls of the shells.The entire header is enclosed in foam rubber insulation 70 and theshells are spaced apart by strips of foam rubber 72.

The header 3-is provided with sixteen nozzles 100 which are positionedrespectively, at the tops of the various freezing tubes. Each of thenozzles includes a water discharge pipe or tube 102 which is welded tothe bottom of shell 60 and projects downwardly unsupported into the topof the freezing tube. Concentrically positioned around tube 102 is anoverflow sleeve or tube 104 which is soldered in the bottom wall ofshell 61 and has its upper end projecting above the center of the waterdischarge passageway 88 in this shell. The lower end of tube 104projects into the top of the freezing tube and has an annular externalgroove 106 thereon from which is supported a target member 110 having apairvof balelike arms 112 and a dish-like target portion 114.

Target member 110 is identical with the similar member 56-59 of theembodiment of Figures 1 to 5 and (see Figure 1l) the upper'ends of arms112 are bent toward each other and are enlarged with arcuate endsurfaces 116. These end surfaces are resiliently held against the bottomof the groove 106 and (see Figure 7) the sponge rubber member whichforms part of insulation 70 presses resiliently against the tops ofthese arms 112, thus to insure that the target member will not becomedislodged. Thus, the nozzle construction provides a water dischargepassageway through tube 102, and the water is directed from thispassageway againstthe stationary target member in the manner discussedabove in connection with the embodiment of Figures 1 to 5.

An overflow discharge outlet is also provided by the annular spacebetween the two tubes 102 and 104 through which water is discharged intopassageway 88, but tube 104- extends upwardly into passageway 88 so thatwater does not flow in the reverse from this passageway into any of thefreezing tubes. Passageway 88 is provided at its right-hand end with avent pipe 108 which prevents abnormal pressure or vacuum conditions tobuild up in the passageway. The water supply pipe 90 which extends fromthe water pump is connected to the right-hand end of shell 60 thus tosupply water to passageway 86 andthe water outlet or discharge pipe 91is connected to shell 61 thus to receive the overflow water frompassageway 88.

The operation of this embodiment is similar to that discussed above, itbeing understood that water under pressure in passageway 86 isdischarged into the freezing tubes. At the end of the freezing operationcold water from one or more of the tubes ows upwardly through therespective tubes 104 and thence through passageway 88 into pipe 91 toinitiate the harvesting operation. The concentric arrangement of thewater supply and discharge passageways of the nozzles has advantagespatricularly under some conditions of operation and with certain typesof machines.

As pointed out above, in both of the illustrative embodiments of thepresent invention the overflow discharge passageway is vented toatmosphere; that is, in Figures 1 to 4 a vent 92 is provided and inFigures 6 to 9 a vent 108 .is provided. As stated, these vents maintainatmospheric pressure in the overow discharge passageway which, asindicated, are open to the tops of the tubes. It has been found thatthis arrangement has particular advantages with ice-making machines suchas those of the illustrative embodiments. With such a machine the normalfreezing behavior in the freezing tubes is that the water flows down thetube walls in an open free ow during the beginning of each freezingcycle. That is to say, the tube is not full of owing water, but there isa rapidly moving sheet of water covering the entire wall surfaces, andthere is a column of air down the center of the tube.

As freezing progresses and the holes in the tubes become smaller, apoint is reached in one or more tubes when there is a sudden bridgingover so that the column of air disappears and there is no longer a freeflowing layer of water; but rather, there is a solid column of waterwhich occupies the entire opening at the center of the aromas Column ofice. This sudden bridging over effect tends to cause a partial vacuumcondition to exist because the solid column of water tends to carry airwith it so that the tube, in effect, acts as an aspirator. The partialvacuum condition is transmitted to the overow discharge passageway andthrough it to the tops of the other tubes, most of which may still havea column of air in them with the free ow of water down their walls. Thiscauses air to ow back up the tubes which still have columns of air inthem at that instant and the upward passage of air tends to interruptthe downward ow of water and water is carried with the air into theoverow discharge passageway. At times this flow has been sufficient toinitiate the harvesting cycle which, as will be understood, is pre`mature because none of the columns is frozen solidly and most of themhave a substantial opening through them.

With the vent arrangement herein disclosed, the partial vacuum conditionis relieved by the vent and, therefore. the partial vacuum condition inone tube is not transmitted to another. Thus, the mode of operationdiscussed above is carried on without danger of the freezing operationbeing stopped prematurely.

Under some circumstances, it is desirable to vary the sizes of thenozzles or otherwise to control the water ilow through them. In this wayit is possible to insure uniform building up of ice where the freezingtubes are cooled at different rates. Thus, in the embodiment of Figures1 to 5 there is a tendency` for the tubes at the two ends of the bank tobe cooled more rapidly because of the cooling eiects of the bends at theends of the runs of the evaporator sections. This non-uniformity ofcooling of the tubes is compensated for by flowing water at a more rapidrate through the two end tubes than through the other tubes. Thus, thegreater quantity of water flowing through these tubes carries away heatmore rapidly, and ice builds up at a slower rate. It is thereforecontemplated that the tlow be so adjusted in each tube as to give thedesired rate of building up of ice; illustratively, the ow through eachtube is somewhat proportional to the rate of heat transfer from thattube.

As many possible embodiments may be made of the mechanical features ofthe above invention and as the art herein described might be varied invarious parts. all without departing from the scope of the invention, itis to be understood that all matter hereinabove set forth, or shown inthe accompanying drawings is to be interpreted as illustrative and notin a limiting sense.

I claim:

l. In ice-making apparatus of the character described a waterdistributor system which includes, a closed water supply header havingoutlets spaced along its bottom wall and adapted to project solidstreams of water respectively into the tops of the various tubes of abank, target means positioned in the tops of the respective tubes in theline of the water ow and adapted to divert the water outwardly andupwardly within each tube against the tube walls thereof, and ventingmeans connected to the tops of said tubes and extending therefrom tosubstantially atmospheric pressure.

2. Apparatus as described in claim l which includes, an overow dischargeheader connected to receive overflow water individually from the tops ofthe tubes and providing said vent means therefor.

3. Apparatus as described in claim 1 wherein the size of the outlet isvaried to control the flow to each tube with respect to the cooling rateso that ice builds up substantially evenly in the various tubes.

4. In ice-making apparatus of the character described, the combinationof, a plurality of vertical freezing tubes which are provided with innerfreezing surfaces which are refrigerated so that ice will form thereonto form ice bodies, and water distributor means to supply water to saidtubes including a header and a plurality of nozzles connected to saidheader and associated respectively with said freezing tubes with eachnozzle projecting into the Lipper end of its tube and having anunobstructed outlet which is circular in cross section and has its axissubstantially concentric with the axis of its freezing tube, each ofsaid nozzles including a deliector positioned in the top of the tube andformed by a plurality of supporting arms and a target portion which issubstantially less in diameter than the smallest transverse dimensionot' the tube whereby there is a substantial free opening, and the waterflow from said water distributor in the various tubes being controlledin substantially a direct relationship to the rate of cooling of eachtube whereby ice builds up at substantially the same rate in each tube.

5. In ice-making apparatus of the character described, the combinationof, a plurality of vertical freezing tubes which are provided with innerfreezing surfaces which are refrigerated so that ice will form thereonto form ice bodies, a water discharge means connected to the top of eachof the tubes and a vent to atmospheric pressure connected to saiddischarge means whereby abnormal pressure conditions in one tube do notsubstantially alter the operations in the other tubes, and waterdistributor means to supply water to said tubes including a header and aplurality of nozzles connected to said header and associatedrespectively with said freezing tubes with each nozzle projecting intothe upper end of its tube and having an unobstructed outlet which iscircular in cross-section and has its axis substantially concentric withthe axis of its freezing tube, each of said nozzles including adetiector positioned in the top of the tube and formed by a plurality ofsupporting arms and a target position which is substantially less indiameter than the smallest transverse dimension of the tube wherebythere is a substantial free opening.

References Cited in the file of this patent UNITED STATES PATENTS250,912 Grinnell Dec. 13, 1881 759,623 Link May 10. 1904 1,021,566 WoodMar. 26, 1912 1,427,822 Kennedy Mar. 1l, 1918 1,674,480 Nelson June 19,1928 2,215,916 Dodd Sept. 24, 1940 2,239,234 Kubaugh Apr. 22, 19412,462,329 Mojonnier Feb. 22, 1949 FOREIGN PATENTS 28,415 Austria May 10,1907 123,762 Germany Sept. 24, 1901

